Door lock



y 1963 E. J. H. FlALA ETAL DOOR LOCK 3 Sheets-Sheet 1 Filed Oct. 18, 1961 m m A M m m m V A N NM NM RL EM y 21, 1963 E. J. H. FIALA ETAL 3,090,644

DOOR LOCK Filed Oct. 18, 1961 3 Sheets-Sheet 2 IN V EN TORfi.

ERNST F IALA ELMAR KAFKA A TTORN E Y5.

May 21, 1963 Filed Oct. 18, 1961 E. J. H. FIALA ETAL DOOR LOCK 5 Sheets-Sheet 3 INVENTORS. ERNST FIALA BY ELMAR KAFKA MMCZ? A TTORNE YS.

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tea 7 Patented May 21, 1963 3,090,6d4 DQOR 196K Ernst J. H. Fiala, Sindeltingen, Kreis Bcblingen, and Elmer Kafka, Esslingen (Ne Paar), Germany, assignors to Daimler-Benz Aktiengeselisehait, Etuttgart-Unterturlrheim, Germany Filed Oct. 18, 1%1, Ser. No. 145,818 Claims priority, application Germany Get. 19, 1969 tllairns. (Q. 292-229) The present invention relates to a closure mechanism provided with a latching device, for lids, doors, etc., especially for motor vehicles having a pivotal sll'fting member which is actuated mechanically, pneumatically or electromagnetically and with a pivotal latching member which is actuated hydraulically.

With closure devices of this type there is released by the use of a relatively small amount of force, for example, by finger pressure, an auxiliary force by means of which takes place the latching and unlatching, for example, of doors of busses. The present invention is based on the underlying problem to create a relatively inexpensive, uncomplicated and safe closure and latching unit in which the door closing and latching takes place hydraulically. In accordance with the present invention, the vehicle door is adapted to be closed and opened noiselessly and with a very small amount of force Whereas the latching itself is to be assured by a relatively large force or blocking effect.

The problem is solved in accordance with the present invention by pivotally connecting at the latch member a hydraulic adjusting motor and a spring in such a manner that the spring forces the latching member into the position opening the door in which the hydraulic adjusting motor is in the dead-center position with respect to the pivot point of the latch member and that the hydraulic adjusting motor is moved out of the dead center position thereof by abutment of the latching member at the door catch and thereby forces the latch member against the force of the spring into the position thereof in which it closes and latches the door, and that upon actuation of the shifting member the latching is rendered inoperative and the latch member assumes the position thereof opening the door and that additional means are provided in order to enable closing and latching of the door also in case of failure of the hydraulic system.

There is produced by such a construction of the closure and latching unit a door closure and latching system having a hydraulic as well as a mechanical actuation so that also in case of failure of the hydraulic pressure the door may be closed and latched.

The auxiliary force, already with a slight abutment of the latching member secured at the door against the door catch secured at the vehicle body, causes the door to close forcibly by means of the adjusting motor and thereupon automatically latches the same. This closing of the door by an auxiliary force is particularly advantageous with passenger motor vemcles since it represents a significant and substantial facilitation when a passenger seated within the vehicle desires to close the door and only needs to pull the door slightly toward him. The slamming of the door which is damaging to the door hinges as well as to the door and to the body is thereby completely eliminated. The door lock with the latching mechanism according to the present invention represents a significant contribution to the present day desire to offer to the driver as large as possible a driving comfort and safety. A force-locking connection between body and door is established by the hydraulic latching so that all rattling noises which have their origin in an excessive play with the usual prior art form-locking connections are obviated.

The construction of the door latch and door catch as mutually adjustable latching members serves, as additional means to the hydraulic auxiliary force, to enable closing and latching of the door even in :case of failure of the hydraulic pressure system. The additional latching can take place, for example, by means of mechanical latching pawls in such a manner that a latching pawl is inserted between the latching member and the shifting member which is adapted to engage into a detent step of the latching member and which, by actuation of the shifting member, may be disengaged from this detent step.

Accordingly, it is an object of the present invention to provide a closure and latching mechanism in which closing and latching normally takes place automatically by the use of an auxiliary force.

Another object of the present invention resides in the provision of a closure and latching mechanism, especially for vehicle doors, in which closing and opening thereof can be realized by the use of a relatively small force while the latching itself is realized by a large force.

Another object of the present invention resides in the provision of a door latch, especially for motor vehicle doors, in which the door, after being moved into a position in which the latching member abuts against the door cat h, is automatically closed and latched whereby closing and latching as well as reopening takes place completely noiselessly.

Still a further object of the present invention resides in the provision of a closure and latching mechanism, especially for a motor vehicle door, in which an auxiliary force actuated by a fluid pressure medium is utilized to effect closing and latching of the door in a completely automatic manner after bringing the door into a position of slight abutment with the door catch in which such automatic closure and latching means is automatically rendered operative.

Still another object of the present invention resides in the provision of a hydraulically actuated door closure and latching means which is so constructed and arranged that the door may be closed and latched even in case of failure of the hydraulic system.

A further object of the present invention resides in the provision of a door latch system of the type described hereinabove which is simple in construction, safe in operation and relatively inexpensive in manufacture, assembly and service.

Another object of the present invention resides in the provision of a door closing and latching mechanism especially for passenger motor vehicles which greatly facilities closing of the door on the part of a passenger seated within the vehicle by making available an auxiliary closing and latching force which is rendered effective automatically when the door is brought into a position in which such auxiliary force can become effective.

Still another object of the present invention resides in the provision of a door closure and latching mechanism which effectively protects the door hinges as Well as the doors and vehicle body against damage and wear caused, for example, by slamming of the door.

Still a further object of the present invention resides in the provision of a door closure and latching mechanism in which a force locking connection between vehicle body and door is established thereby eliminating the rattling noises caused by an excessively large play that occurs frequently in the prior art form-locking constructions.

These and other objects, features and advantages of the present invention will becomemore obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein FIGURE 1 is an elevational view of a closure and latch ing unit in accordance with the present invention as seen in the plane of the door cross section;

FIGURE 2 is a side elevational View of the closure and latching unit of FIGURE 1;

FIGURE 3 is an elevational view in the same plane as FIGURE 1 of a modified embodiment of a closure and latching unit in accordance with the present invention;

FIGURE 4 is a partial side View. of the unit of FIGURE 3, and

FIGURE 5 is a partial plan view of the closure and latching unit of FIGURE 3.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate corresponding parts, more particularly to FIGURES l and 2, reference numeral 1 generally designates therein the closure and latching unit which is secured at the side panel of the door 3 by any suitable means such as screws Z. The closure and latching unit may be acted upon by a manual push button 4 arranged in the door handle 34 or by a spring-loaded bell-crank 3t operatively connected with the interior door opening means as well as by a latching member generally designated by reference numeral 5. The vehicle body side wall 7 together with the door catch 3 secured at the body is indicated in FIGURE 1 next to the sidewall 6 of the door facing the vehicle interior space.

In FIGURE 1, the door 3 is placed lightly against the vehicle body and the latch member 5 and the catch are in contact with each other. The latching member 5 is brought into abutment against the adjusting screw 16 with the nose '51 thereof by means of spring 9. The latch member 5 is a three-armed lever and is piyotally supported about the bearing bolt 11 secured to the base plate '18. The piston 12 of the adjusting motor generally designated by reference numeral 13 is secured on one side thereof by a pivotal connection 14 at the latching member 5 and on the other side thereof is arranged axially slidable within the cylinder 15 of the adjusting motor 13. The cylinder 15 is secured by a pivotal connection 16 at a lug portion '17 of the base plate 18. The latch member 5 is brought into abutment by the adjusting screw 10 in such a manner that the axis of the adjusting motor 13 passes through the pivot point of the bearing bolt support 11 whereby the latch member 5 cannot be actuated with the piston 12 acted upon by the pressure medium. The line 19 of the hydraulic auxiliary force is connected to the nipple 21) at the cylinder 15. This line 119 terminates within a hydraulic switching or shifting device generally designated by reference numeral 21. The shifting device 21 is also secured on the base plate 18. The line 19 may be selectively connected by means of the hydraulic shifting mechanism 21 with a line 22, through which the pressure fluid is supplied to the adjusting motor 13, and with a line 23 through which the pressure fluid medium can be discharged from and flow out of the adjusting motor 13. The shifting mechanism 21 is mechanically shifted by the lever 24 over shifting pins 53 and 55. In the position illustrated in FIGURE 1, the shifting member 21 is so shifted by means of the shifting pin 53 that the piston '12 of the adjusting motor '13 is loaded by the pressure fluid. The lever 24. is ,pivotally arranged about the bearing bolt 25 within the shifting mechanism 21 and is pivotable as well as displaceable within an elongated aperture 26 provided within the arm 46 of the shifting member 27. The shifting member 27 is also a three-armed lever which is pivotally supported about the bearing bolt 28 secured in the base plate 18, The shifting member 27 is brought into abutment with the arm 50 thereof against the knee portion or projection of the bell crank 30 by the spring 29. The bell crank'fiil is pivotally supported about the bearing bolt 33 secured in the angularly-bent rim portion of the base plate 18 and is brought into abutment against the latch pocket 44 by a pre-stressed spring 41. The spring 29 is arranged at the connecting point 3 1 on the shifting member 27 and through the connecting point 54- is supported over a knee portion or projection 32 at the base plate 18. The manually actuated push button 4 acts on the third arm 42 of the shifting member 27. A springloaded latching pawl 35 which is pivotally supported about a bearing bolt 35 secured in the base plate 18 is arranged between the shifting member 27 and the latch member 5. The latching pawl 35 comes into abutment, pretensioned by the spring 37, against the latch member 5. The latch member 5 is provided with a detent step or notch 3-5 for the latching pawl 35'. By reason of the pin 4% secured at the shifting member 27, the latching pawl 35, upon swinging of the shifting member 27 in the counterclockwise direction, is also pivoted in the counterclockwise direction and the nose portion 49 of the latching pawl 35' is thereby moved out of the engaging area for the detent step 38. i j

' Operation The operation of the closure and latching unit of FIG- URES 1 and 2 in accordance with the present invention is as follows:

As shown in FIGURES l and 2, the door is in the opened position thereof. The door catch 8 and door latch 5 are out of engagement. The piston 12 of the adjusting motor 13, loaded by the pressure fluid, exerts a force on the bolt 11, however, without producing a moment on the latch member 5 so that the latch member 5 is not pivoted or swung thereby. The pressure fluid acts on the piston 12 through the line 22, shifting or switching mechanism 21 and line 19. If, in this opened door position, the manual push button 4 at the outer door handle is actuated or the bell crank 31 is actuated through the inner door han le, then only the shifting mechanism 221 is alternately actuated. Consequently, under these conditions of manual actuation, the piston '12 of the adjusting motor '13 is alternately subjected to fluid pressure or relieved therefrom. The closure and latching operation, however, is not initiated alone by such actuation. If, however, the door 3 is moved in the direction against the door catch s, i.e., if the door is to be closed, then the latch member 5 comes into abutment against the door catch 8. As a result thereoflthe latch member 5 slides slightly upwardly along the track 43 of the door catch 8 and is rotated in a clockwise direction against the force of spring 9 whereby the axis of the adjusting motor 13 no longer passes through the support of the bolt 11. The piston 12 of the adjusting motor 13 which is loaded by pressure fluid now rotates the latch member '5 in a clockwise direction and the arm 47 of the latch member 5 slides, along the track 43 of the door catch 8 into the pocket or recess 48 and therewith closes and latches the door 3. It therefore suffices, in order to close and latch the door, if the door is placed with a very slight pressure against the vehicle body. Consequently, the adjusting motor 13 acting on the latch member 5 forces the door into closing without any further manipulation. The door is retained in the latched position thereof by the piston 12 which, during latching, is loaded by the pressure fluid supplied through line 22. If the door is to be opened, either from the outside or from the vehicle interior space, then the manual push button 4- is pressed in or the bell crank 30 is rotated in the clockwise direction by a linkage, not illustrated in the drawing, which engages with the bell crank 36' at the pivotal connection 45.

As a result thereof, the shifting member is rotated in the counterclockwise direction against the force of spring 29 and shifts with the arm 45 thereof through lever 24 the shifting mechanism 21 in such a manner that the pressure fluid can flow out of the adjusting motor 13 through the line 19 and the shifting mechanism 21 into the discharge line 23. The adjusting motor 13 thereby becomes pressureless. The spring '9 swings the latch member 5 again into the position thereof shown in FIGURE 1 and the door is opened thereby. If, for any reason, the adjusting motor 13 should fail, i.e., the piston 12 of the adjusting motor 13 can no longer be loaded by pressure fluid, then the closing of the door 3 takes place in the manner that by pushing or slamming the door 3, the arm 47 of the latch member 5 slides along the track 43 of the catch 8 into the pocket 48. The latch member 5 is retained in this position in which the door is closed by the latching pawl 35. The latching pawl 35 slides along the detent step 38 during swinging of the latch member 5 and thereby engages the detent provided therefor. During opening of the door, i.e., upon actuation of the manual push button 4 or of the bell crank 3-9, the latching pawl 35 is swung in the counterclockwise direction out of the detent step 38 by the pin 40 secured .at the shifting member 27, and the spring 9 can thereupon return the latch member 5 back into the door opening position shown in the drawing. The detent step or notch 38 is so arranged at the latch member 5 that with a hydraulic closing and latching of the door 3, the nose portion 49 of the latching pawl 35 is not supported in the corner of the latching step or detent 38 so that during opening of the door the latching pawl 35 only has to be pivoted against the small force of the spring 37. In order to avoid the snap-in noise which occurs during engagement of the latching pawl 35 in the detent step 33 during closure of the door, the pin 49 is advantageously covered with any suitable elastic material and the latching pawl 35 is not permitted to impinge against the bottom or base of the detent step 38. The closure and latching unit in accordance with the present invention may be locked by any suitable known locking means in or operatively associated with the push button 4 whereby the shifting member 27 can no longer be actuated. The closure and latching unit may also be locked, however, by the fact that by means, not illustrated herein, the discharge path through line 19 and through the shifting mechanism 21 as Well as through the discharge line 23 is closed off in any suitable place. As a result thereof, notwithstanding actuation of the shifting member 27, the pressure fluid can no longer escape from the adjusting motor 13.

FIGURES 3 to 5 show a further embodiment of the door closing and latching mechanism in accordance with the present invention.

Those parts of FIGUPTS 35 which correspond to similar parts in FIGURES 1 and 2 are designated with corresponding reference numerals with prime marks added, The closure and latch unit is illustrated in PEG- URES 3 to 5 with a closed vehicle door. The lever 24' for the actuation of the shifting mechanism 21 is thereby rigidly connected with the shifting member 27' so that the lever 24' and shifting member 27 are supported together on the bearing bolt 25' in the shifting mechanism 21'. The latch member 5 and the door catch 8' cooperate as in FIGURE 1 only that the pocket or recess 4-8 is formed in this embodiment by the latching member 5 and the arm sliding into the pocket 43 is formed by a part of the door catch 8'. The spring 9 and the adjusting motor 13 are pivotally secured at the same point 14' at the latch member 5. The conical pin 52' secured in the door catch pocket 44 serves in a manner known per se for the guidance of the door within the door aperture of the vehicle body and provides a support of the door in the vehicle longitudinal direction with respect to the vehicle body. The pin 49' provided with an elastic cover material is arranged in this embodiment at the latching pawl 35'. The lug 32 is adjustable in the transverse direction so that the position of the connecting point 54 of the spring 29 is adjustable relative to the connecting point 25 of the shifting member 27. The connecting point 54 is so located that in the illustrated position, that is, with a non-actuated shifting member 27, the connecting point 31' is disposed toward the right outside of the line of connection between the connecting points 54 and 25' so that the shifting member 27 with a non-actuated manual push button 4- or bell crank 3%, is always in the position illustrated in the drawing in which it actuates the shifting mechanism 21' by means of the shifting pin 53. If the shifting member 27 is actuated, that is, if the shifting member 27' is rotated in the clockwise direction, then a shifting position for the shifting mechanism 21 is reached in which the lever 24' secured at the shifting member 27' acts on the shifting pin 55' of the shifting mechanism 21' whereby the points of connection 25, 31 and 54' not yet lie in a straight line, i.e., in a dead center position for the force of a spring 29'. If, however, the shifting member 27 is rotated further, then the connecting point 31 arrives at first in the line of connection of the connecting points 25' and 54, .and thereupon comes to lie on the left side of this connecting line. The force of the spring 2? now acts in addition to the actuating force against the resistance of the shifting pin 55 of the shifting mechanism 21'. The actuation of the closure and latch unit takes place as a result thereof with a slight amount of force. If the shifting member 27' is no longer actuated, then the shifting member 27 is rotated in the counterclockwise direction by the resistance of the shifting pin 55, and more particularly through the dead center position for the force of the spring, i.e., until the connecting point 31 is again disposed toward the right of the line connecting the connecting points 25' and 54. The further pivoting of the shifting member 27 is then realized by the force of the spring 29'.

While we have shown and described two embodiments in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of many changes and modifications within the spirit and scope thereof, and we therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A closure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in the dead center position with respect to the pivot point of said latch means and that said hydraulic adjusting means is moved out of the dead center position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, and means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position thereof, and additional means to enable closing and latching of said door in case of failure of said hydraulic adjusting means.

2. A closure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in the dead center position with respect to the pivot point of said latch means and that said hydraulic adjusting means is moved out of the dead center position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position there of, means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position, and additional means to enable closing and latching of said door in case of failure of said hydraulic adjusting 7 means including latching pawl means between said shifting means and said latch means and adapted to engage a detent provided within said latch means, said latching pawl means being effectively disengaged from said detent upon actuation of said shifting means.

3. A closure mechanism provided with latching means, comprising pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in an inefiectual position thereof and that said hydraulic adjusting means is moved out of said inefiectual position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, and means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latching means into the door-opening position thereof.

4. A closure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in an ineffectual position thereof and that said hydraulic adjusting means is moved out of said ineffectual position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, and means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position thereof, and additional means to enable closing and latching of said door in case of failure of said hydraulic adjusting means.

5. A closure mechanism for lids, doors and the like, especially for motor vehicle doors, comprising hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, and means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means forces said latch means into the door opening position thereof in which sm'd hydraulic adjusting means is effectively inoperative and that said hydraulic adjusting means is automatically rendered effective by abutment of said latch means at said catch means to thereby force said latch means against the force of said spring means into ,the door closing and latching position thereof, manually operated means operative for returning said latch means into said effectively inoperative position, and additional means to enable closin and latching of said door in case of failure of said hydraulic adjusting means.

6. A ciosure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising a hydraulic shifting mechanism having two shifting positions, pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in the dead center position with respect to the pivot point of said latch means and that said hydraulic adjusting means is ment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position, and additional means to enable closing and latching of said door in case of failure or" said hydraulic adjusting means including latching pawl means between said shifting means and said latch means and adapted to engage a detent provided within said latch means, said latching pawl means being effectively disengaged from said detent upon actuation of said shifting means, further spring means for retaining said shifting means in one end position thereof in which said latching pawl means is adapted to be eifectuahsaid shifting means being operatively associated in said last-mentioned one end position with said hydraulic shifting mechanism in such a manner that said hydraulic shifting mechanism causes said hydraulic adjusting means to be subjected to the pressure of the fluid pressure medium, and said hydraulic shifting mechanism being brought into the other end position thereof upon actuation of said shifting means against the force of said further spring means to enable discharge of the fluid pressure medium from said adjusting means.

7. A closure mechanism for lids, doors andthe like, especially for motor vehicle doors, comprising hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, and means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means forces said latch means into the door opening position thereof in which said hydraulic adjusting means is effectively'inoperative and that said hydraulic adjusting means is automatically rendered effective by abutment of said latch means at said catch means to thereby force said latch means against the force of said spring means into the door closing and latching position thereof, and manually operated means operative for returning said latch means into said effectively inoperative position.

8. A closure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising a hydraulic shifting mechanism having two shifting positions, pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in an effectively inoperative center position wi-th respect to the pivot point of said latch means and that said hydraulic adjust ng means is moved out of the efiectively inoperative position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position, and additional means to'enable closing and latching of said door in case of failure of said hydraulic adjusting means including latching pawl means between said shifting means and said latch means and adapted to engage a detent provided within said latch means, said latching pawl means being effectively disengaged from said detent upon actuation of said shifting means, further spring means for retaining said shifting means in one end position thereof in which said latching pawl means is adapted to be effectual, said shifting means being operatively associated in said last-mentioned one end position with said hydraulic shifting mechanism in such a manner that said hydraulic shifting mechanism causes said hydraulic adjusting means to be subjected to the pressure of the fluid pressure medium, and said hydraulic shifting mechanism being brought into the other end position thereof upon actuation of said shifting means against the force of said further spring means to enable discharge of the fluid pressure medium from said adjusting means.

9. A closure mechanism provided with latching means for lids, doors and the like, especially for motor vehicle doors, comprising pivotal shifting means, hydraulically actuated pivotally arranged latch means, catch means for said latch means, hydraulic adjusting means, spring means, means operatively connecting said adjusting means and said spring means with said latch means in such a manner that said spring means normally forces said latch means into the door opening position thereof in which said hydraulic adjusting means is in the dead center position with respect to the pivot point of said latch means and that said hydraulic adjusting means is moved out of the dead center position thereof by abutment of said latch means at said catch means and thereby forces said latch means against the force of said spring means into the door closing and latching position thereof, means operative upon actuation of said shifting means for rendering said latch means inoperative and for returning said latch means into the door-opening position, and additional means to enable closing and latching of said door in case of failure of said hydraulic adjusting means including latching pawl means between said shifting means and said latch means and adapted to engage a detent provided within said latch means, said latching pawl means being effectively disengaged from said detent upon actuation of said shifting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,874,482 Forman Aug. 30, 1932 2,601,983 Schoelkopf July 1, 1953 2,896,990 Garvey et al July 28, 1959 2,898,138 Van Noord Aug. 4, 1959 2,910,318 Masur Oct. 27, 1959 2,950,138 Meyer et al Aug. 23, 1960 

3. A CLOSURE MECHANISM PROVIDED WITH LATCHING MEANS, COMPRISING PIVOTAL SHIFTING MEANS, HYDRAULICALLY ACTUATED PIVOTALLY ARRANGED LATCH MEANS, CATCH MEANS FOR SAID LATCH MEANS, HYDRAULIC ADJUSTING MEANS, SPRING MEANS, MEANS OPERATIVELY CONNECTING SAID ADJUSTING MEANS AND SAID SPRING MEANS WITH SAID LATCH MEANS IN SUCH A MANNER THAT SAID SPRING MEANS NORMALLY FORCES SAID LATCH MEANS INTO THE DOOR OPENING POSITION THEREOF IN WHICH SAID HYDRAULIC ADJUSTING MEANS IS IN AN INEFFECTUAL POSITION THEREOF AND THAT SAID HYDRAULIC ADJUSTING MEANS IS MOVED OUT OF SAID INEFFECTUAL POSITION THEREOF BY ABUTMENT OF SAID LATCH MEANS AT SAID CATCH MEANS THEREBY FORCES SAID LATCH MEANS AGAINST THE FORCE OF SAID SPRING MEANS INTO THE DOOR CLOSING AND LATCHING POSITION THEREOF, AND MEANS OPERATIVE UPON ACTUATION OF SAID SHIFTING MEANS FOR RENDERING SAID LATCH MEANS INOPERATIVE AND FOR RETURNING SAID LATCHING MEANS INTO THE DOOR-OPENING POSITION THEREOF. 